14. The signal flow graph of a system is shown below The number of terms in the determinant (A) of SFG except the unit term areConsider the following statements in respect of introducing feedback in a control system. I. The feedback in a control system is employed to reduce sensitivity, improve transient response and minimize the effect of disturbance signals. Il. The signal to noise ratio of feedback sensor must be high. Ill. The feedback increases the range of frequencies over which the system can be made to respond desirably. Of these (a) only I and II are true. (b) only Lis true. (c) only I and III are true. (d) I. Wand II all are true.9. A signal flow graph of a system is shown below. G Go G, Consider the following statements regarding the SFG. 1. Two forward paths and five individual loops. Three forward path and three pairs of two non-touching loops. Total number of individual loops and the number of pairs of two non — touching loops are reduced by equal number, if branch of SFG having gain Ge is removed. There are three pair of two non - touching loops.Which of the following is correct? (a) 1,3 and4 (b) 2,3 and 4 (c) 3 and 4 only (d) 1 and 3 only6. For the signal flow graph shown below KK, =99, s= jl rad/s, and G= 4 10s+1 l G 1 K, The sensitivity of the closed-loop to variation in parameter K is approximately (a) 0.01 (b) 0.1 (c) 1.0 (d) 105. A -system block diagram is shown in the given figure. The overall transfer function of the system is c_ GGG; R1+G,G,G3H, +GyH, —G,G,H, The value of *X’ would be equal (a) Hs (b) GiH3 (c) G2H3 (d) G3H3In a negative, non-unity feedback system G = 10,000 and H=0.01. The gain G decreases from 10,000 to 5000. The transfer function decreases by (a) 0.5% (b) 10% (c) 5% (d) 100%2. Study the following statements: 1. A closed loop control system is usually more accurate than the open loop control system. 2. Feedback is sometimes used to improve the sensitivity of a control system. 3. If an open loop system is unstable, applying feedback will always improve its stability. Which one of the above statements(s) is(are) incorrect)? (a) 1,2 (b) 2,3 (c) 3,1 (d) None3. Consider the block diagram shown in figure RQ) S COs) GiG2 1+G,H, +G,G,H, +G,G,H, (a) GiG2 bp) ——— re ®) 1+G,H) +G,G,H; +G,G,H,H, GG ©) 1 6@)H) +G,G,H, +6,6,F,H,H, GiG2 (@ ———_2 ___ 1+G,H, +G,G,H; +G,G,H,H;1. The signal flow graph of a system is shown below. The transfer functions u y,=0 is 8 Ys G, Ye GY; 1 Me, Hy (a) G,G;(1-G,H)) (b) G,Gs(1+G2H)) A A © GsGs (d) None AThe transfer function of the system shown below is GG, +G,G, by) 22+ Gs 1-G,H, +G)G; 1+ G3H, — GG; GGs+GGs — qy) _G2+GGs 1+G3H, +G,G; 1-G3H, -G)G; (a) (c)5. For the system shown below transfer function C(s) / R(s) is G3 (a). —— —t__ 1-H \G, — HG; -G,G,H, tt) G+GG, 1+ HG, + HG; +G,G,H, () ——_& 1+ AiG, + H2G3 +G,GyH2 @) G 1— HG, — HG; —G,GzH6. For the block diagram shown below, the numerator of function is (a) Ge [Gy + Gs +Gs (G3 +G) | (b) Ge[ Gy +G; +G5(G3+G,)] (0) Gs[G, +G,+G;(G,+G;) | (d) None of the aboveWhe block diagram shown in tigure (a) can be reduced as a block diagram as shown in figure (b). The parameters m and n respectively are. Figure (a) Q in P PG+Q Figure (b) 11 G,G b) == (a) (b) GG 1 d) Gj qd) GConsider the block diagram shown in figure, Which of the following is an equivalent graph of above system is x +1 c(s) (a) x * ¥ y () y oe c(s) x x + e(s) © x : y * + — e(S) @ x» Mark List) (Original Diagram) with List-i. (Equivalent Diagram) and select the correct answer using the codes given below the Lists: List-I (Original Diagram) Gh Zz R z Ye + x G |} )}—2 a lsh-$ Y List-II (Equivalent Diagram) x > chk 1 2 Ye G x + Gre 4. ol Zz Y<4uG ze Q Rk Ss (@) 3 1 4 2 (b) 2 4 1 3 © 3 4 1 2 @2 1 4 3, The block diagram shown in figure I and figure — IT are equivalent for the value of P = . s°+5s+6The unit-step response of a system starting form rest is given by c(t) = 1-e for t > 0. The transfer function of the system is: 1 2 (a) 142s (b) Dts «@ @ 2+s 14+2sSelect the correct transfer function Vo(s)/Vi(s) from the following for the given network. b s ”) s(s +1) eS (s +2) Ss 2s (2s +1) (s +1) (c)A differential equation for a LTI system with specified input and initial conditions is dy(t) d?y(t) _dy(t fy), FV, v( J. x(x) dt dt dt All initial conditions are zero, x(t) = 10e~* the system output is (a) [2 +5e' 507 + 3e'|u (t) (b) [2-se “t 450 > Se) © 2u(t)—5u(t—1)+5u(t-2)+3u(t-3) @) u(t) +5u(t-1)—5u(t-2)+3u(t-3)Consider a signal x(t) = e‘u(t) and Laplace transform pair x(t} +5Xx(s) . Match list I (Laplace transform) with list II (inverse Laplace transform) and choose the correct answer using the code given below. List-I List-II (Laplace Transform) (Inverse Laplace Transform) P. sX(s) 1, (1-e%),t>0 Q. X(s) 2. et u(t-2) s R. X(2s) 3. -ett>0 S. © X(s) 4, Fer"u(t) odes: P Q R Ss (a) 4 2 1 3 (b) 3 1 4 2 (c) 1 3 2 #4 (d) 3 4 1 2Consider a system described by following differential equations with initial condition dy(t SU) 10y(0) =2x(0),y(0") =4x(e)=u() Output of the system will be (a) 2t+de™ u(t) () Etr4e"™) (c) =3(1+ 46 Ju (d) —2 (1446)Given that L[F(t)]= she ELs()] Stl oefreete-den then (s+3)(s+2) L[(h(t)] is s? +1 (a) s+3 1 (b) = () x? +1 4 St? (s+3)(s+2) s?41 (d) None of the aboveThe correct representation of the response c(t) for the following system, if a unit impulse signal is applied on input side is R(s) cy) (a) (b) 1 caw o4 8! cw C(t) (c) , (d) 1 t 4 tThe Laplace transform of the function 2e+ — e** j s+5 b 2s+6 (@) (any(s+3) (©) ean(s+3) s—5 d 2s —5 ©) Teynlss3) @) es3)Servomechanisms are , Where the feedback signals are used to control position, speed, velocity, acceleration, etc. (a) adaptive control systems (b) open loop control systems(c) closed loop control systems (d) optimal control systemsThe control system in which the output quantity has no effect upon the input quantity are called control system. (a) Open loop (b) Closed loop (c) Variable (d) Non -— variableOpen loop transfer function of a closed loop control system is defined as: (a) Actuating signal/feedback signal (b) Output/feedback signal (c) Output/actuating signal (d). Feedback signal/actuating signalAutomatic washing machine is example of (a) Closed loop system (b) Open loop system (c) Both (a) & (b) (d) None of the above